Transition-metal-catalyzed Difunctionalization Of Alkanes With ?Bpin?₂

Over the past few decades,transition-metal catalyzed difunctionalization of alkenes has received widespread attention from chemists because of their ability to rapidly construct complex structure molecules.Among them,the difunctionalization of alkenes involved in?Bpin?₂ is studied type of reaction relatively,and a series of novel methods for constructing complex compounds have emerged in this field.This thesis focused on copper-and palladium-catalyzed difunctionalization of alkenes,and by using the role of?Bpin?₂ in the reaction process,two novel reaction protocols were developed successfully:1)Cu?I?-catalyzed intramolecular 5-exo-trig radical cyclization/borylation of unactivated iodides;2)Pd?0?-catalyzed regiocontrollable hydroarylation reaction of allenamides.While studying and summarizing the bifunctionalization of alkenes involved in?Bpin?₂,on the basis of reasonable experimental designs and screening for catalytic conditions,we have realized the Cu?I?-catalyzed intramolecular 5-exo-trig radical cyclization/borylation of unactivated iodides that accompany the construction of aquaternary carbon:access to functionalized pyrrolidine derivatives,which are widely existed in pharmaceuticals and bioactivated molecules.The study indicates that there is a fundamental chemoselectivity issue,which is a radical cyclization of alkyl halides.In addition,the reaction has the characteristics of mild conditions,high chemoselectivity,and high efficiency.In addition,on the basis of the role of?Bpin?₂/H2O in the reaction,we have developed the Pd?O?-catalyzed regiocontrollable hydroarylation reaction of allenamides.This transformation utilizes H2O as hydrogen source.Compared to“sacrificial" hydrogen sources,such as silicon hydride,alcohols,formic acid,Hantzsch esters,hydrazine,etc.,water has been regarded as an ideal hydrogen donor because of its abundance and environmentally benign.More importantly,The regioselectivity is achieved by adjusting the addition order of catalyst and iodobenzene derivatives.Based on deuterium-labeled experiment and TEMPO testing experiment,the possible reaction pathway was proposed,and the regulation of regioselectivity was explained.